battery education sought

[Chuck Guzis]

On 10/16/2005 at 11:36 PM ard at p850ug1.demon.co.uk wrote:

>To go OT for a momnet, a lot of 1950's/1960's cameras used a mercury cell 
>to power the exposure meter. The constant voltage meant the circuit could 
>be very simple (just the CdS photoresistor, the mercury cell, a 
>microammeter movement and a couple more resistors, generally). Now that 
>such cells are unobtainium, there are various kludges, some of which work 
>better than others, but it's still a pain.

Modern silver-oxide batteries have very stable voltage-vs-discharge
characteristics.  My 1960's Nikon F2 Photomic uses a pair and does just
fine.

http://www.sony.net/Products/MicroBattery/sr/

--Chuck